Abstract: This paper presents a cubic graph by which it is unnecessary to decompose each monomial into miniterms for minimizing multivariate switching functions of single-output. The method for obtaining "non-redundant" cover and the method which is called "orded array method" for finding "minimal" cover are also presented; The minimization of switching functions with more than six variables that cannot be solved by Karnaugh graph, may be solved by these methods. Souch methods can be applied to the simplification of logic circuits, digital control etc. The algorithms presented in this paper has been implemented on the computer C'J-719.